Horizontally expandable, silage storage bags are commonly used as an alternative to permanent feed storage structures such as barns and silos. From an economic standpoint, an expandable plastic storage bag is preferable to a more elaborate, permanent structure. Further, the expandable bags are more easily loaded with feed than permanent structure and the silage stored therein is readily accessible for use, for example using a small tractor with a front bucket to unload the feed.
An exemplary prior art bagger is described in U.S. Pat. No. 5,878,552 (which patent is incorporated herein in its entirety by reference), to Paul R. Wingert, the present applicant. A tractor-powered bag-loading apparatus is disclosed in association with an expandable bag. A backstop is located at the filled end of the bag and has attached thereto laterally spaced cables, which extend forward to rotatable cable drums on the bagger machine. The drums are yieldably braked and, under a predetermined force applied to the cables, release the cable to allow movement of the bag-loading apparatus and tractor away from the filled end of the bag as it is filled. The bag is filled by a toothed rotor, which propels silage through a tapered tunnel and into the bag inlet. The tapered tunnel described in U.S. Pat. No. 5,878,552 provides a smooth, more evenly filled bag.
The bag for use with such bagging machines is manufactured and delivered in a pleated shape, i.e., folded into an accordion-bellows-type shape. Typically, a bag having a nominal ten-foot-diameter (approximately 3 meters diameter, or 9.6 meters circumference) and a 300-foot length (approximately 90 meters length) will be folded to a 10-foot-diameter (about 3 meters) ring about one foot (about 0.3 meter) long and 1 foot (about 0.3 meter) thick. To start the loading operation, this bag-ring is pre-loaded around the tunnel, and the pleats are unfolded one at a time as the bag is deployed and filled with feedstock. Once any portion of the bag fills with feed, that portion becomes very heavy, and does not move. Thus the bagger machine itself is propelled along the ground in front of the bag being filled.
One exemplary bagging machine is described in U.S. patent application Ser. No. 09/721,268 filed on Nov. 22, 2000, entitled “Improved Agricultural Feed Bagger and Method” by Paul R. Wingert, the inventor of the present application. U.S. patent application Ser. No. 09/721,268 is incorporated in its entirety by reference. In some embodiments of the present invention, a large conveyer-belt bed, as described in U.S. patent application Ser. No. 09/721,268, is provided for loading voluminous quantities of agricultural material into its hopper.
One contends with numerous problems in using previous bagging structures. For example, there is a safety problem caused by feed that bridges within the tapered input hopper. Persons may be tempted to unclog the hopper by stomping or otherwise inserting an arm or a leg thus risking being sucked through and shredded by the primary compression mechanism. U.S. patent application Ser. No. 09/977,036 (incorporated herein by reference) filed Oct. 11, 2001 by Paul R. Wingert, the inventor of the present invention, provided several embodiments that churned the feed to prevent bridging of feed in the input hopper, and that had fixed safety shields over portions of the moving parts. Apparatus and methods for increasing compaction in the upper tunnel were also described.
As more fully described in patent application Ser. No. 09/977,036, one way to help prevent bridging is to churn or move the feed in hopper, for example using an arm that moves in a curvical motion, since it is connected to arm that moves in a circular motion driven by motor (e.g., a hydraulic motor, in some embodiments), and arm is also connected to arm that moves in a wiper-blade motion. Thus the curvical motion of arm helps prevent feed from bridging against sloping wall by moving feed towards rotor. Sloping shield wall provided additional safety by enclosing much of the moving part of the arm, and much or all of arms and. However, now bridging could occur against the stationary sloping shield wall, although this was further from rotor and at a portion of chute that was larger in cross sectional area, so the bridging problem was reduced.
Conventional baggers also suffer from an inability to adequately compact feed in the upper and lower portions of the tunnel, thus leaving the feed in the lower bag highly compacted and the feed in the upper bag only moderately compacted. Conventional baggers also suffer from inability to efficiently force large amounts of feed into the bag while providing a variable control on the tunnel opening to control the amount of feed compaction.